Data Source

Variable Descriptions and Summaries

Variables include:

## Rows: 50
## Columns: 7
## $ GEOID     <chr> "51109950202", "51109950300", "51079030200", "51079030102", …
## $ area_0    <dbl> 205.412595, 514.588394, 134.848897, 253.775954, 8.605687, 34…
## $ area_1per <dbl> 16.389151, 35.367836, 8.618762, 14.870029, 0.691124, 11.9287…
## $ area_2per <dbl> NA, NA, NA, NA, 0.107866, 0.355381, 0.134962, 0.818826, 0.31…
## $ perc_0    <dbl> 92.53404, 93.51768, 93.99951, 94.46401, 91.50433, 96.58924, …
## $ perc_1per <dbl> 7.382967, 6.427502, 6.007905, 5.535129, 7.348727, 3.304043, …
## $ perc_2per <dbl> NA, NA, NA, NA, 1.14693997, 0.09843366, 0.08842507, 0.849198…
  • GEOID: geographic identifer for spatial area (tracts, block groups, and blocks)
  • area_0: area (in km^2) of block/block group/tract/county that do not intersect with 100-year or 200-year floodplains, or areas with minimal chance of flooding.
  • area_1per: area (in km^2) of block/block group/tract/county that intersects with 100-year floodplain, or areas with a 1% annual chance of flooding.
  • area_2per: area (in km^2) of block/block group/tract/county that intersects with 100-year floodplain, or areas with a 2% annual chance of flooding. This zone is also used to designate base floodplains of lesser hazards, such as areas protected by levees from 100-year flood, or shallow flooding areas with average depths of less than one foot or drainage areas less than 1 square mile.
  • perc_0: percentage of block/block group/tract/county that does not overlap with the 1% or 2% annual flood zone.
  • perc_1per: percentage of block/block group/tract/county that overlaps with the 1% annual flood zone.
  • perc_2per: percentage of block/block group/tract/county that overlaps with the 2% annual flood zone.

5-number summaries of variables by block groups:

## 
## Summary Statistics
## ========================================
## Statistic Mean St. Dev. Min Median  Max 
## ----------------------------------------
## area_0    54.2   71.1   0.3  16.0  358.0
## area_1per 4.4    5.7    0.0  2.0   26.8 
## area_2per 0.2    0.3    0.0  0.1    2.0 
## perc_0    93.2   6.7    64   94.2   100 
## perc_1per 7.0    5.7    0.0  6.3   29.1 
## perc_2per 0.8    1.5    0.0  0.2    7.8 
## ----------------------------------------

Visual Distributions

Tracts

Percent of tract in minimal flood, 1% annual floodplain, and 2% annual floodplain zones

Block Groups

Percent of block group in minimal flood, 1% annual floodplain, and 2% annual floodplain zones

Blocks

Percent of block in minimal flood, 1% annual floodplain, and 2% annual floodplain zones

Maps

1% Annual Flood Zone

Tracts

Block Groups

Blocks

Block level maps are slow to render and may be added later.

2% Annual Flood Zone

Tracts

Block Groups

Blocks

Block level maps are slow to render and may be added later.